class_docstr: A helper class to implement a renderer that switches between
  vector and raster drawing.  An example may be a PDF writer, where
  most things are drawn with PDF vector commands, but some very
  complex objects, such as quad meshes, are rasterised and then
  output as images.
docstr: Enter "raster" mode.  All subsequent drawing commands (until
  stop_rasterizing is called) will be drawn with the raster
  backend.
  
  If start_rasterizing is called multiple times before
  stop_rasterizing is called, this method has no effect.
docstr_tok: ["Enter","``","raster","''","mode",".","All","subsequent","drawing","commands","(","until","stop_rasterizing","is","called",")","will","be","drawn","with","the","raster","backend",".","If","start_rasterizing","is","called","multiple","times","before","stop_rasterizing","is","called",",","this","method","has","no","effect","."]
code: def start_rasterizing(self):
      """
      Enter "raster" mode.  All subsequent drawing commands (until
      stop_rasterizing is called) will be drawn with the raster
      backend.
  
      If start_rasterizing is called multiple times before
      stop_rasterizing is called, this method has no effect.
      """
  
      # change the dpi of the figure temporarily.
      self.figure.set_dpi(self.dpi)
  
      if self._bbox_inches_restore:  # when tight bbox is used
          r = process_figure_for_rasterizing(
              self.figure, self._bbox_inches_restore
          )
          self._bbox_inches_restore = r
  
      if self._rasterizing == 0:
          self._raster_renderer = self._raster_renderer_class(
              self._width * self.dpi, self._height * self.dpi, self.dpi
          )
          self._set_current_renderer(self._raster_renderer)
      self._rasterizing += 1
  
file_path: catboost/contrib/python/matplotlib/py2/matplotlib/backends/backend_mixed.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import numpy
  import six
  from matplotlib.backends.backend_agg import RendererAgg
  from matplotlib.tight_bbox import process_figure_for_rasterizing
label_desc: Use image node_id 3 for calling the MixedModeRenderer obj's underlying member method code with example usage: obj.start_rasterizing() without return types